Conventionally, the following configuration exists as an example of this kind of flow rate measurement apparatus (for example, refer to patent document 1):
Generally, a gas meter incorporating a gas flowmeter attached to the entrance of a gas supplying pipe line in each household.
To execute the gas-appliance-based fee system in the conventional gas meter, using a plurality of integrating meters connected to the gas meter, the integrated flow rate for use in a specific time zone and the integrated value for use of the flow rate in a specific range, namely, the flow rate by time zone and the flow rate by flow rate class are found and the fee system is determined according to the integrated values. An example of the fee system will be discussed based on FIG. 24. A predetermined discount flow rate class and a predetermined discount time zone are set the gas fee of the flow rate corresponding to the discount flow rate class and the discount time zone is to be discounted. That is, the portion hatched in FIG. 24 is discounted. In this method, however, determination of an appliance is ambiguous and it is difficult to make a fee setting easier to understand and more convenient for the consumer such as charging a fee for a specific appliance. Then, the following is proposed as a method for determining a specific appliance (for example, refer to patent document 2):
The operation of the proposal example is as follows: FIG. 25 shows a gas flow rate change pattern at the starting time of one gas appliance and reference values for pattern matching based on the pattern (pattern table). For one gas appliance, it is necessary to provide as many pattern tables as the number of flow rate change patterns of a sequence of gas occurring accompanying combustion control of the gas appliance and it becomes necessary to provide as many pattern tables as the total number of gas appliances used in each household. While change in the flow rate value measured by the flow rate measurement apparatus of the gas meter and the pattern tables are always compared, the matching target is extracted and the appliance is determined.
If a flow rate pattern other than the registered appliances occurs in the measured gas flow rate, a system of informing the user of the fact and making a request for storing the flow rate pattern also exists (for example, refer to patent document 3).    Patent document 1: Japanese Patent Laid-Open No. 2002-71421    Patent document 2: Japanese Patent Laid-Open No. 2003-149027    Patent document 3: Japanese Patent No. 3490064